Some Important Points To Remember When Servicing Piston Rings; Measuring Piston Ring End Gap; Measuring Piston Ring Side Clearance; Install Piston Rings - Kohler Courage SV470 Service Manual

Some important points to remember when servicing
piston rings:
1. If the cylinder bore is within the wear limits (refer
to Section 1) and the old piston is within wear
limits, free of score or scuff marks, the old piston
may be reused.
2. Remove old rings and clean up grooves. Never
reuse old rings.
3. Before installing the rings on the piston, place
each of the top two rings in its running area in the
cylinder bore and check the end gap (see Figure
9-13). Compare to the listed specifications.
Top and Middle Compression Ring End Gap
New Bore
Top Ring .....................0.15/0.40 mm (0.006/0.016 in.)
Middle Ring ............... 0.30/0.55 mm (0.012/0.022 in.)
Max. Used Bore .........0.77 mm (0.030 in.)
Figure 9-13. Measuring Piston Ring End Gap.
4. After installing the new compression (top and
middle) rings on the piston, check piston-to-ring
side clearance. The maximum recommended side
clearance for each ring is 0.04 mm (0.0016 in.). If
the side clearance is greater than specified, a new
piston must be used. Refer to Figure 9-14.
Top Compression Ring-to-Groove
Side Clearance ................................0.04 mm (0.0016 in.)
Middle Compression Ring-to-Groove
Side Clearance ............................... 0.04 mm (0.0016 in.)
Inspection and Reconditioning
Figure 9-14. Measuring Piston Ring Side
Clearance.

Install Piston Rings

To install piston rings, proceed as follows:
NOTE: Rings must be installed correctly. Ring
installation instructions are usually included
with new ring sets. Follow instructions
carefully. Use a piston ring expander to
install rings. Install the bottom (oil control)
ring first and the top compression ring last.
Refer to Figure 9-15.
Piston Ring
End Gap
Identification
Mark
Oil Control Ring
(Three Piece)
Figure 9-15. Piston Ring Installation.
Section 9
Piston
Top Compression
Ring
Center Compression
Ring
Rails
Expander
9.11
9